1. Field of the Invention
The invention in general relates to RF circuitry, and more particularly to an improved superregenerative receiver which may also be operated as a transmitter.
2. Description of Related Art
Superregenerative receivers are often utilized in applications requiring small size, low power consumption and inexpensive circuitry. For example, superregenerative receivers find utility in small beacons, transponders, toys and remote control applications, to name a few.
In one information transfer arrangement, a plurality of RF modems are utilized, in conjunction with respective host devices, to effect the information transfer. An improved such arrangement is more fully described and claimed in copending patent application Ser. No. 09/310,219, filed May 12, 1999, assigned to the same assignee as the present invention and hereby incorporated by reference. The RF modems described therein employ a superregenerative circuit as a receiver and, preferably, as a transmitter as well.
It is known that the radiation of any superregenerative receiver, when in the receive mode, is quite substantial, so that as a consequence, interference problems may be experienced if several devices must operate in the vicinity of one another. In addition, various such superregenerative circuits do not necessarily faithfully reproduce the received signal.
The present invention provides an improved superregenerative circuit which is relatively small and inexpensive, with reduced power consumption, and can be utilized in an environment wherein a plurality of such circuits are simultaneously operating. Further, a sampling of the received signal in accordance with an improved technique, results in a more accurate representation of the received signal.
An RF superregenerative circuit is provided which is operable as a receiver as well as a transmitter of RF signals. The circuit includes a superregenerative oscillator having an amplifier, a resonant circuit arrangement connected to the output of the amplifier and feedback means connecting the resonant circuit arrangement with the input of the amplifier. Circuit means are provided for controlling the oscillatory condition of the oscillator. A signal decoupling means is connected in circuit between the oscillator and an antenna means and is operable to minimize any RF energy radiated by the superregenerative circuit, via the antenna means, when in the receive mode of operation.